package com.yc.yn.netty;

import io.netty.channel.Channel;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.handler.timeout.IdleState;
import io.netty.handler.timeout.IdleStateEvent;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * @Description: 用于检测channel的心跳handler
 * 继承ChannelInboundHandlerAdapter，从而不需要实现channelRead0方法
 */
public class HeartBeatHandler extends ChannelInboundHandlerAdapter {
	private final static Logger log = LoggerFactory.getLogger(HeartBeatHandler.class);

	@Override
	public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {

		// 判断evt是否是IdleStateEvent（用于触发用户事件，包含 读空闲/写空闲/读写空闲 ）
		if (evt instanceof IdleStateEvent) {
			IdleStateEvent event = (IdleStateEvent) evt;        // 强制类型转换

			if (event.state() == IdleState.READER_IDLE) {
				log.debug("进入读空闲...");
			} else if (event.state() == IdleState.WRITER_IDLE) {
				log.debug("进入写空闲...");
			} else if (event.state() == IdleState.ALL_IDLE) {

				log.debug("channel关闭前，users的数量为：" + ChatHandler.users.size());

				Channel channel = ctx.channel();
				// 关闭无用的channel，以防资源浪费
				channel.close();

				log.debug("channel关闭后，users的数量为：" + ChatHandler.users.size());
			}
		}

	}

}
